Determination of Sucrose

In addition to such an extension of the spectrum of measurable compounds, enzyme sequences are also useful to enhance the selectivity of indicator reactions, e.g., in GOD-HRP electrodes, and to enhance the sensitivity, e.g., in thermistors using a GOD-catalase sequence. These 

Another type of sequential coupling is provided by cycling reactions. The product of the primary enzyme reaction is regenerated to the substrate of this reaction, i.e., the analyte, in a second, enzyme-catalyzed reaction. These cycles are based on the dependence of the two enzymes on different cofactors thus, the required free enthalpy exists for both reactions. The analyte molecule may be regarded as a catalyst of the reaction between the two cofactors. This results in a rate of cofactor conversion and enthalpy production that is enormously higher than that in a single enzyme reaction. These cycling reactions therefore lead to a substantial increase of sensitivity. 

Parallel coupling constitutes another type of coupled enzyme reactions. This includes the competition of two enzymes for a common substrate as well as the conversion of alternative substrates and the competitive binding of a substrate and an inhibitor to an enzyme. Thus, analytes become measurable even though they cannot be converted to readily detectable products. Coupled enzyme reactions can also be used to eliminate disturbances of the enzyme or transducer reaction caused by constituents of the sample. Compounds interfering with the signal transduction can be transformed into inert products by reacting them with an (eliminator) enzyme which can be coimmobilized with the analyte-converting (indicator) enzyme in the vicinity of the transducer. On the other hand, constituents of the sample which are at the same time intermediate products of coupled enzyme reactions and will thus 

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DETERMINATION OF SUCROSE AS ITS TRIMETHYLSILYL DERIVATIVE USING GAS-LIQUID CHROMATOGRAPHY... 

Figure 3.14 — (A) Flow injection system for the determination of glucose in the presence of interfering compounds. (Reproduced from [92] with permission of Elsevier Science Publishers). (B) Flow injection manifold for the simultaneous determination of sucrose and glucose. (Reproduced from [93] with permission of the American Chemical Society).

The continuous configurations depicted in Figs 5.12.D1 and 5.12.D2 were designed by Nieman s group for application of this sensor to the determination of sucrose (and glucose) in soft drinks, breakfast cereal and cake mix [36]. The analyte is converted into /3-D-glucose, to which the sensor is responsive, in two reaction steps that are catalysed by invertase (INV) and mutarotase (MUT) ... 

Anon (1998a) Determination of sucrose enzymatic. No. 56, in International Federation of Fruit Juice Producers (IFU) Handbook of Analytical Methods, Swiss Fruit Juice Union, Zug, Switzerland. 

E. Maestre, I. Katakis and E. Dominguez, Amperometric flow-injection determination of sucrose with a mediated tri-enzyme electrode based on sucrose phosphorylase and electrocatalytic oxidation of NADH, Biosens. Bioelectron., 16(1-2) (2001) 61-68. 

T. Hu, X.E. Zhang, Z.P. Zhang and L.Q. Chen, A screen-printed disposable enzyme electrode system for simultaneous determination of sucrose and glucose, Electroanalysis, 12 (2000) 868-870. 

The determination of sucrose in the microbiological and food industry is of a similar importance as the determination of glucose in the clinical laboratory. Sucrose consists of (3-D-fructose and a-D-glucose linked to each other by the glycosidic OH-groups ... 

Various research groups have developed enzyme electrodes for the determination of sucrose. The operational parameters of these sensors are listed in Table 10. 

Fig. 78. Determination of sucrose with immobilized invertase and a GOD electrode, (a) Measuring cell, (b) Measuring curves of successive assay of glucose and sucrose. 1 current indication (/), 2 kinetic indication (d//df).

Matsumoto et al. (1988) coupled enzyme reactors for the elimination of glucose and ascorbic acid with enzyme reactors for the determination of sucrose, glucose and fructose in an FLA manifold. 

E.A.G. Zagatto, I.L. Mattos, A.O. Jacintho, Determination of sucrose in sugar-cane juice and molasses by flow-injection spectrophotometry, Anal. Chim. Acta 204 (1988) 259. 

Murakami Y, Takeuchi T, Yokoyama K, Tamiya E, Karube I and Suda M 1993 Integration of enzyme-immobilized column with electrochemical flow cell using micromachining techniques for a glucose detection system Anal. Chem. 65 2731-5 Olson B, Stalbom B and Johansson G 1986 Determination of sucrose in the presence of glucose in a flow Injection system with immobilized multi-enzyme reactors Anal. Chim. Acta 179 203-8... 

More elaborate systems incorporating a series of reactors have been described by a Swedish group in Lund, which has also conducted a number of theoretical studies on optimization of the design of packed reactors in FIA systems [344, 345]. Thus, Olsson et al. [1067] have devised a procedure for determination of sucrose based on the following sequence of reactions ... 

M. Masoom and A. Townshend, Simultaneous Determination of Sucrose and Glucose in Mixtures by Flow Injection Analysis with Immobilized Enzymes. Anal. Chim. Acta, 171 (1985) 185. 

C. A. Koerner and T. A. Nieman, Chemiluminescence Flow Injection Analysis Determination of Sucrose Using Enzymatic Conversion and a Micro-porous Membrane Flow Cell. Anal. Chem., 58 (1986) 116. 

B. Olsson, B. Stalbom, and G. Johansson, Determination of Sucrose in the Presence of Glucose in a Flow-Injection System with Immobilized Multi-Enzyme Reactors. Anal. Chim. Acta, 179 (1986) 203. 

Polarimetry The determination of sucrose and reducing sugars in fruit and fruit products by polarimetry is an AOAC recommended method. The polarimeter measures the rotation of plane polarized light caused by a solution containing an optically active compound. Separate measurements for the quantification of sucrose and reducing sugars can be made with the Clerget-Hertzfeld double-polarization method. 

Sucrose In contrast to most other disaccharide splitting enzymes, invertase (EC 3.2.1.26) produces enough heat to allow direct determinations of sucrose in the range of 0.05-100 mmol 1 , even in... 

Based on the above inadequacy of pH measurements and the variability in sucrose determinations by different analytical methods we stress a cautious approach in the interpretation of fundamental research data in the industrial environment. It seems likely that empirical equations for estimation of sucrose loss have little application, and obviously, the results of experimental determination of sucrose loss during evaporation will be dependent on the choice of analytical methods. 

Certainly, the most accurate determination of sucrose loss across any unit process in sugar manufacture would consist of analysis for a marker compound that is an end product of sucrose hydrolysis and monosaccharide degradation, and that could be directly related to sucrose loss. Unfortunately, no likely marker compound has been identified. Preliminary GC-MS analysis of MJ and 3rdS samples from this study indicate that most identifiable compounds (e.g., kestoses) are present in both MJ and 3rdS. 

Lenkey, B., Csanyi, J., and Nanasi, P. (1986). A rapid determination of sucrose and fructose in biological samples by video densitometry. J. Liq. Chromatogr. 9 1869-1875. 

H. Abe, S. Kawano, K. Takehara, M. Iwamoto. Determination of Sucrose content in Sugarcane Juice by Near Infrared Spectroscopy, Rep Natl Food Res Inst 60 31-36. Tsukuba, Japan Food Research Institute, 1996. 

Thavarungkul, P., P. Suppapitnarm, P. Kanatharana et al. 1999. Batch injection analysis for the determination of sucrose in sugar cane juice using immobilized invertase and thermometric detection. Biosens. Bioelectron. 14 19-25. 

Hamid JA, Moody GJ, Thomas JDR. Chemically immobilised tri-enzyme electrode for the determination of sucrose using fiow injection analysis. Analyst 1988 113 81. 

Palmer JK, Braudes WB. Determination of sucrose, glucose, and fructose by liquid chromatography. J Agric Food Chem 1974 22 709 712. 

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